NEW YORK (July 2, 2009)--Those familiar with Michael Jackson's vaults say the pop star has left behind a trove of unreleased music.

Executives and lawyers who know the material anticipate the swelling demand of fans should be satisfied with unreleased tracks from studio sessions of some of Jackson's best albums, as well as more recently recorded songs made with Akon and will.i.am.

Tommy Mottola, the former chairman and CEO of Sony Music, which owns the distribution rights to Jackson's music, described the unreleased material as "endless."

Mottola said new and repackaged releases "could go on for years and years - even more than Elvis."